This invention relates to tools for crimping sheet metal clasps around overlapped lengths of strap, and in one aspect to such a tool which is manually operated.
Many prior art tools are known for crimping sheet metal clasps around overlapped lengths of strap to attach the lengths of strap together. Included are tools for crimping a known prior art type of sheet metal clasp particularly adapted for use on non-metallic strap such as the No. 315 clasp available from Minnesota Mining and Manufacturing Co., St. Paul, Minn. This type of clasp includes a generally planar base portion having a serrated contact surface with a width between first and second parallel edges generally corresponding to the width of the strap to be joined; and a generally curved top portion with a serrated inner surface joining the base portion along the first parallel edge of the contact surface, projecting over the base portion in a spaced relationship to afford positioning overlapped lengths of strap therebetween, and being adapted to overlap the base portion when pressed over the overlapped lengths of strap thereon with the distal edge of the top portion along the second edge of the base portion. The clasp also includes a locking lip projecting generally normal to the base portion toward the top portion along the second edge of the contact surface, and having a height affording engagement thereof over the distal edge of the top portion to lock the top portion in place after the top portion is pressed over overlapped lengths of strap between the top and base portions.
One known type of tool for crimping the clasp described above is sold by A. Konrad, Feinmechanik A.G., Merenschwand, Switzerland and designated KO76. This tool is a combination crimping and tensioning tool which includes a base adapted to locate a clasp through which overlapped lengths of strap are positioned, and means for manually driving a die block into engagement with the top portion and locking lip of a located clasp to crimp the clasp. While this tool will securely crimp the clasp on non-metallic strap, it is quite complex and thus more expensive than may be desired for many applications. Additionally, with this tool only one edge of the die block can roll the locking lip over the top portion of the clasp, so that the workman must always orient the clasp on the tool with its locking lip along a predetermined edge of the die block.